1. Field of the Invention
The present invention relates to a golf club provided with a hollow head and to a die for golf club head to cast a hollow golf club head.
2. Description of the Prior Art
Conventionally, hollow club heads made of metals were manufactured by precision casting called lost wax process which uses wax material, or the method disclosed in Japanese Utility Model Application Laid-open Print No. 61-33970, where a hollow head body is formed by joining three pieces into one.
However, in this method disclosed in Utility Model Application Laid-open Print No. 61-33970, a divided piece is provided with a fixed pipe for shaft mounting resulting in heavy weight, and division into three pieces cause errors during manufacturing process, for example, in the position of shaft hole in relation with the face, which impedes providing of precise golf club head.
In conventional lost wax method, it was relatively difficult to obtain a uniform head and to position a shaft hole with high precision.
Further, in conventional golf clubs made of metal materials, the golf shafts were inserted through the neck to heel of the head body. However, since the path for golf shaft insertion was formed as a solid part, it was quite difficult to improve precision of shaft hole position, and to reduce the club weight.